1. Field of the Invention
The present invention relates to fluorescent lighting systems and devices.
2. The Prior Art
Fluorescent lighting in compact versions, such as Philips' U.S. Pat. No. 4,199,708 and the well known CIRCLINE have been replacing incandescents in their myriad applications for many years. However, fluorescent replacements for reflective incandescents such as R30, R40 and PAR38 lamps have been notable for their inadequate lumen output. The many compact versions of reflective lamps have used U-shaped lamps, twin lamps, quad lamps and other assorted geometries. These reflective compacts have also demonstrated significant dimensional incompatibilities caused by awkwardly long straight lengths of fluorescent tubes.
Typically, today's compact fluorescent reflective assembly has its tubing axes in line with its screw-in base thereby presenting the smallest tubing surface area to the illuminated object. This orientation lowers net lumen output as light emanated from most of the tubing has to reflect a multiplicity of times to emanate from the overall lamp assembly, losing lumen output with each reflection. Quad tubing arrangements and triple twin arrangements also limit their lumen output as much of their original light is directed inward toward the other tubes, thus significantly reducing the total light emanating from the overall assembly. Hardwired ceiling fixtures using quads and twins also have significant lumen loss even though they are mounted horizontally with respect to the typical illuminated surface or object. These losses stem from the fact that they block their own light when mounted in close proximity to the top of the fixture. As in the screw-in floodlamp version using quads, hardwired ceiling fixtures employing quads also have significant light lost internally to their own lamping structure.
U.S. Pat. No. 4,833,574 by Gallagher uses multiple annular tubes to generate large amounts of light, but, significantly, this patent's use of square tubing arrangements in different planes also demonstrates large inefficiencies. For example, Gallagher's use of two square tubes directly on top of each other creates a tubing configuration which results in the immediate loss of three-eights of the fluorescing light generated because three of the eight sides have no exposure to the illuminated object.
The many manifestations of reflective compact fluorescent lamps, including U.S. Pat. No. 5,130,910 and 4,723,200, have large inherent lumen losses, particularly when quad type tubes are the light source. For example, the Phillips compact reflective SL18/R40 EARTH LIGHT using U-shaped tubing, claims an 800 lumen output. It is expected that the embodiment of this invention will exceed 1600 lumens, thus approaching the typical 1730 lumen output of 150 watt PAR 38 incandescents. The situation as described makes it apparent that the lumen output of today's fluorescent reflective lamps and ceiling fixtures, such as described in U.S. Pat. No. 4,947,297, can be greatly improved. Great improvement can also be made by creating fluorescent reflective lamps similar to incandescent reflector shapes while generating comparable light output.